The present invention relates to a medical image processing apparatus for supporting an examination, diagnosis, and therapy using a catheter and the like.
According to a conventional therapeutic method for aneurysms, an incision is surgically made in a patient""s body to expose a morbid portion (aneurysm), and the neck of the exposed aneurysm is fastened with a clip to prevent blood from flowing into the aneurysm.
Recently, however, a great deal of attention has been given to a low-invasive therapeutic method represented by IVR (InterVentional Radiology). The low-invasive therapeutic method is also applied to a therapy for aneurysms. For example, a catheter is inserted into a patient""s body from the groin to an aneurysm through a blood vessel. This operation is performed with a guide of a blood vessel image (to be referred to as a xe2x80x9ccontrast imagexe2x80x9d hereinafter) whose contrast is enhanced by a contrast agent. When the catheter reaches the aneurysm, a coil-like occlusive material 200 shown in FIG. 1 is injected from the distal end of the catheter into the aneurysm to fill the aneurysm with the occlusive material 200. The blood then stagnates in the aneurysm filled with the occlusive material 200. The stagnant blood coagulates after a while. With this operation, a therapeutic effect similar to that of a clip therapy can be obtained.
There are various occlusive materials 200 with different materials, shapes, sizes, and the like. Selecting the occlusive material 200 having a suitable size for the size of the internal portion of the aneurysm is important to attain a desired therapeutic effect. To three-dimensionally grasp the size of the internal portion of the aneurysm, a plurality of blood vessel extraction images acquired by DSM (Digital Subtraction Angiography) at a plurality of projection angles are used.
Such blood vessel extraction images are acquired after a surgical operation. A therapeutic effect is checked by comparing these blood vessel extraction images after the surgical operation with those acquired before the surgical operation. In general, to improve the precision of this therapeutic effect check, blood vessel extraction images are acquired after a surgical operation at the same projection angles as those before the surgical operation.
As described above, contrast images and blood vessel extraction images acquired at a plurality of projection angles are very effective in grasping the 3D structure of a target.
The power of expression of contrast images and blood vessel extraction images is not sufficient to grasp the complicated structure of a blood vessel. For this reason, it may take much time to move a catheter to a target. In addition, it may take much time to search for optimal projection angles, or radiography may need to be repeated many times at various projection angles to obtain detailed depth information.
Furthermore, blood vessel extraction images are acquired to check an occlusive material therapy and medical therapeutic effect in a catheter therapy. To perform this check, images of the aneurysm and nearby portions are required, but images of portions outside them are not required. In this case, X-rays with which these outside portions are irradiated will cause unnecessary exposure to X-rays.
It is an object of the present invention to provide an image which effectively supports an operator in grasping the 3D structure of a blood vessel in a medical image processing apparatus.
According to the present invention, in a medical image processing apparatus, a storing unit stores first 3D image data corresponding to a first period and second 3D image data corresponding to a second period. The first 3D image data corresponds a period before condition changing. The second 3D image data corresponds to a period after condition changing. A 3D subtracting unit subtracts the first 3D image data from the second 3D image data. In 3D subtraction image data, a portion that has changed due to the condition changing is emphasized. The pseudo 3D image data generating unit generates pseudo 3D image data on the basis of the 3D subtraction image data. A display unit displays pseudo 3D image data.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.